SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc0e89d2f63e25b31a7d58161670066ba2af617a44d00814510bc96cc23765b8' 
  AND token = 'yEG9P3RhKcDtez2G/ikm46jl5sSh/J9xARwlN4nXwtk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}